TY - JOUR A1 - Vogl, Jochen A1 - Quétel, C. A1 - Ostermann, Markus A1 - Papadakis, I. A1 - Van Nevel, L. A1 - Taylor, P.D.P. T1 - Contribution to the certification of B, Cd, Mg, Pb, Rb, Sr, and U in a natural water sample for the International Measurement Evaluation Programme Round 9 (IMEP-9) using ID-ICP-MS JF - Accreditation and quality assurance N2 - The present paper describes the contribution of the Institute for Reference Materials and Measurements to the certification of B, Cd, Mg, Pb, Rb, Sr, and U amount contents in a natural water sample, in round 9 of the International Measurement Evaluation Programme (IMEP-9). The analytical procedure to establish the reference values for B, Cd, Mg, Pb, Rb, Sr, and U amount contents was based on isotope dilution inductively coupled plasma-mass spectrometry used as a primary method of measurement. Applying this procedure reference values, traceable to the SI, were obtained for the natural water sample of IMEP-9. For each of the certified amount contents presented here a total uncertainty budget was calculated using the method of propagation of uncertainties according to ISO and EURACHEM guidelines. The measurement procedures, as well as the uncertainty calculations are described for all seven elements mentioned above. In order to keep the whole certification process transparent and so traceable, the preparations of various reagents and materials as well as the sample treatment and blending, the measurements themselves, and finally the data treatment are described in detail. Explanations focus on Pb as a representative example. The total uncertainties (relative) obtained were less than 2% for all investigated elements at amount contents in the pmol/kg up to the high 7mol/kg range, corresponding to low 7g/kg and mg/kg levels. KW - IMEP-9 KW - ID-ICP-MS KW - IDMS KW - Uncertainty budget KW - Certification PY - 2000 DO - https://doi.org/10.1007/s007690000145 SN - 0949-1775 SN - 1432-0517 VL - 5 SP - 272 EP - 279 PB - Springer CY - Berlin AN - OPUS4-7216 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -